1. Technical Field
The present invention relates to a technique for ejecting liquid, such as ink, by utilizing a piezoelectric element.
2. Related Art
Heretofore, there has been proposed a liquid ejection head having a structure that allows liquid inside each of a plurality of pressure chambers thereof to be ejected through a nozzle by allowing a piezoelectric element associated with the relevant pressure chamber to vibrate a vibration plate constituting a wall of the relevant pressure chamber. For example, in JP-A-2014-83797, there is disclosed a piezoelectric element in which a piezoelectric material layer is formed between a first electrode that is individually formed for each of a plurality of piezoelectric elements and a second electrode that is formed across the plurality of piezoelectric elements. The first electrode, which is linearly formed along a corresponding pressure chamber, extends up to the outside of the pressure chamber in a plan view (that is, the first electrode crosses a short side of the pressure chamber in a plan view), and an edge on the extended side of the first electrode is electrically connected to external wiring. Japanese Patent No. 3,114,808 is also an example of related art.
In the piezoelectric material layer, stress is likely to arise at the boundary between a region that is deformed due to a piezoelectric effect in accordance with electric field between the first electrode and the second electrode (hereinafter, this region will be referred to as “a movable portion”) and a non-movable portion other than the relevant movable portion. Meanwhile, in a vibration plate, a region along the short side of the pressure chamber is less likely to be deformed than a region along a long side of the pressure chamber. In the configuration disclosed in JP-A-2014-83797, since the first electrode is formed so as to cross the short side of the pressure chamber in a plan view, a deformation, which occurs in the piezoelectric material layer due to the stress that arises in a region close to the boundary between the movable portion and the non-movable portion, is suppressed by the vibration plate and, as a result, the piezoelectric material layer is likely to be broken (burned out).